SymmetricDS is

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

software for database and file synchronization with

Multi-master replication Multi-master replication is a method of database replication which allows data to be stored by a group of computers, and updated by any member of the group. All members are responsive to client data queries. The multi-master replication system i ...

, filtered synchronization, and transformation capabilities. It is designed to scale for a large number of nodes, work across low-bandwidth connections, and withstand periods of network outage. Data synchronization occurs asynchronously from a scheduled job, with data changes being sent over a push or pull operation. It uses standard web protocols (

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, ...

) and database technologies (

JDBC Java Database Connectivity (JDBC) is an application programming interface (API) for the programming language Java, which defines how a client may access a database. It is a Java-based data access technology used for Java database connectivity. I ...

) in order to support a wide range of platforms and maximize its interoperability. It includes support for

Oracle An oracle is a person or agency considered to provide wise and insightful counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. As such, it is a form of divination. Description The word '' ...

MySQL MySQL () is an open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, and "SQL", the acronym for Structured Query Language. A relational database o ...

MariaDB MariaDB is a community-developed, commercially supported fork of the MySQL relational database management system (RDBMS), intended to remain free and open-source software under the GNU General Public License. Development is led by some of the ori ...

PostgreSQL PostgreSQL (, ), also known as Postgres, is a free and open-source relational database management system (RDBMS) emphasizing extensibility and SQL compliance. It was originally named POSTGRES, referring to its origins as a successor to the In ...

Greenplum Greenplum is a big data technology based on MPP architecture and the Postgres open source database technology. The technology was created by a company of the same name headquartered in San Mateo, California around 2005. Greenplum was acquired ...

, SQL Server, SQL Server Azure,

HSQLDB HSQLDB (''Hyper SQL Database'') is a relational database management system written in Java. It has a JDBC driver and supports a large subset of SQL-92, SQL:2008, SQL:2011, and SQL:2016 standards. It offers a fast, small (around 1300 kilobytes ...

, H2,

Derby Derby ( ) is a city and unitary authority area in Derbyshire, England. It lies on the banks of the River Derwent in the south of Derbyshire, which is in the East Midlands Region. It was traditionally the county town of Derbyshire. Derby gai ...

, DB2,

Firebird Firebird and fire bird may refer to: Mythical birds * Phoenix (mythology), sacred firebird found in the mythologies of many cultures * Bennu, Egyptian firebird * Huma bird, Persian firebird * Firebird (Slavic folklore) Bird species ''Various spe ...

Informix IBM Informix is a product family within IBM's Information Management division that is centered on several relational database management system (RDBMS) offerings. The Informix products were originally developed by Informix Corporation, whose I ...

Interbase InterBase is a relational database management system (RDBMS) currently developed and marketed by Embarcadero Technologies. InterBase is distinguished from other RDBMSs by its small footprint, close to zero administration requirements, and multi-g ...

SQLite SQLite (, ) is a database engine written in the C programming language. It is not a standalone app; rather, it is a library that software developers embed in their apps. As such, it belongs to the family of embedded databases. It is the most ...

, Sybase ASE, Sybase ASA,

MongoDB MongoDB is a source-available cross-platform document-oriented database program. Classified as a NoSQL database program, MongoDB uses JSON-like documents with optional schemas. MongoDB is developed by MongoDB Inc. and licensed under the Serve ...

Amazon_Redshift Amazon Redshift is a data warehouse product which forms part of the larger cloud-computing platform Amazon Web Services. It is built on top of technology from the massive parallel processing (MPP) data warehouse company ParAccel (later acquired ...

, and

VoltDB Volt Active Data (formerly VoltDB) is an in-memory database designed by Michael Stonebraker, Sam Madden, and Daniel Abadi. It is an ACID-compliant RDBMS that uses a shared-nothing architecture, and is derived from work done by Stonebraker on OLTP ...

databases.

Functionality

SymmetricDS runs either as a standalone server (using a built-in

Jetty A jetty is a structure that projects from land out into water. A jetty may serve as a breakwater, as a walkway, or both; or, in pairs, as a means of constricting a channel. The term derives from the French word ', "thrown", signifying somet ...

), within an application server (such as

Apache Tomcat Apache Tomcat (called "Tomcat" for short) is a free and open-source implementation of the Jakarta Servlet, Jakarta Expression Language, and WebSocket technologies. It provides a "pure Java" HTTP web server environment in which Java code can also ...

), or embedded into an application. Configuration is done through properties files and a collection of configuration tables at a central node. Both database tables and filesystems can be synchronized across a network of nodes. Configuration allows for selection of tables, columns (vertical filtering), and subsets of rows (horizontal filtering) to synchronize in one direction or both directions. Files are selected by base directory and whether to recurse into directories. Wildcard characters are used to match multiple tables and files. Tables can be grouped into channels that sync based on priority. Groups of nodes are linked together and assigned a transport method of push or pull. A push will connect to the node and send changes when they are ready, while a pull will periodically connect with a node to check if changes are available. Several network topologies are possible by linking node groups, including fan-in/out, multi-master, star, and multi-tier tree. A node can be prepared with an initial load of data to populate its database. Changes are grouped into batches and assigned for delivery to nodes using Routers. Routers can be configured or scripted to filter data and make decisions on which nodes should receive data. Batches are delivered during synchronization and tracked using a sequence number and status, with periodic retries designed to automatically recover from errors. Administration tools for command line and a web-based JMX console are included to manage nodes from a central location. Programming interfaces for

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

and

REST Rest or REST may refer to: Relief from activity * Sleep ** Bed rest * Kneeling * Lying (position) * Sitting * Squatting position Structural support * Structural support ** Rest (cue sports) ** Armrest ** Headrest ** Footrest Arts and entert ...

are included to extend and customize behavior.

Prominent users

OpenMRS OpenMRS is a collaborative open-source software, open-source project to develop software to support the delivery of health care in developing countries. OpenMRS is founded on the principles of openness and sharing of ideas, software and strateg ...

- open source medical record system * Openboxes - supply chain management software

References

{{Reflist

External links

SymmetricDS community website

SymmetricDS source code
Data synchronization

Functionality

Prominent users

See also

References

External links